ave increased in numbers
but little in many years since they are always warring among
themselves."

Now we swung a little north of west, leaving the valley of lost souls,
and shortly I discerned over our starboard bow what appeared to be a
black mountain rising from the desolate waste of ice. It was not high
and seemed to have a flat top.

Xodar had left us to attend to some duty on the vessel, and Phaidor and
I stood alone beside the rail. The girl had not once spoken since we
had been brought to the deck.

"Is what he has been telling me true?" I asked her.

"In part, yes," she answered. "That about the outer valley is true,
but what he says of the location of the Temple of Issus in the centre
of his country is false. If it is not false--" she hesitated. "Oh it
cannot be true, it cannot be true. For if it were true then for
countless ages have my people gone to torture and ignominious death at
the hands of their cruel enemies, instead of to the beautiful Life
Eternal that we have been taught to believe Issus holds for us."

"As the lesser Barsoomians of the outer world have been lured by you to
the terrible Valley Dor, so may it be that the therns themselves have
been lured by the First Born to an equally horrid fate," I suggested.
"It would be a stern and awful retribution, Phaidor; but a just one."

"I cannot believe it," she said.

"We shall see," I answered, and then we fell silent again for we were
rapidly approaching the black mountains, which in some indefinable way
seemed linked with the answer to our problem.

As we neared the dark, truncated cone the vessel's speed was diminished
until we barely moved. Then we topped the crest of the mountain and
below us I saw yawning the mouth of a huge circular well, the bottom of
which was lost in inky blackness.

The diameter of this enormous pit was fully a thousand feet. The walls
were smooth and appeared to be composed of a black, basaltic rock.

For a moment the vessel hovered motionless directly above the centre of
the gaping void, then slowly she began to settle into the black chasm.
Lower and lower she sank until as darkness enveloped us her lights were
thrown on and in the dim halo of her own radiance the monster
battleship dropped on and on down into what seemed to me must be the
very bowels of Barsoom.

For quite half an hour we descended and then the shaft terminated
abruptly in the dome of a mighty subterranean world. Below us rose and